Enter roof area and profile to get exact sheet count and order quantity with waste allowance.
Use pitch area calculator for sloped roofs
Corrugated iron has a 762 mm cover width. A 3 m sheet covers 0.762 × 3 = 2.286 m². For 80 m² you need 80 / 2.286 = 35 sheets, plus 10% waste = 39 sheets to order. Enter your exact area and length in the calculator above.
Trafco and 5-rib metal roofing panels have a cover width of approximately 900 mm when lapped. This is wider than corrugated iron (762 mm), so fewer sheets are needed for the same area.
A standard waste allowance for metal roofing is 10% for simple gable roofs. Allow 15% for hip roofs or roofs with multiple penetrations, valleys or dormers. The calculator defaults to 10% but you can adjust this.